Hiawatha is a secure and advanced Web server for Unix. It has been written with security as its main goal. It features advanced access control, prevention of SQL injection and cross-site scripting, banning of clients who try such exploits, the ability to run CGIs under any UID/GID you want, and many other features. These features make Hiawatha an interesting Web server for those who need more security than what the other available Web servers are offering. Hiawatha is also fast and easy to configure.

Zentyal Server aims at offering small and medium businesses (SMBs) a native drop-in replacement for Windows Small Business Server and Microsoft Exchange Server which can be set up in less than 30 minutes and is both easy to use and affordable.

Collax Business Server is an all-in-one Linux server for small- and medium-sized businesses. It delivers all the important network services within a heterogeneous business environment for communication, infrastructure, compliance, groupware, and storage, all in a reliable and secure way which is easy to manage. It also provides essential security functions such as firewalling and virus and spam filtering, to protect against hacker attacks, viruses, and unsolicited email messages.

WAWAS is a full PHP application server.
The main server core listens to any IP/port and passes data to any mounted protocol on the listener. Implemented protocols are HTTP1.1/1.0, Comet, Telnet, DNS, mail, and FTP. Each protocol runs modules that build response data based on the requests. Memory object persistence allows data and caches to be shared across protocols or time. All configuration uses XML. It can be launched as a daemon, with or without forked workers, and is nearly as fast as Apache in preliminary tests.

QtWebApp allows you to write standalone Web server applications in C++ as easily as Java Servlets. The HTTP 1.1 server supports persistent connections, sessions with cookies, and file uploads. It contains a template engine and a logger that can be configured at runtime. The application runs on Unix as a daemon, on Windows as a service, and on all operating systems on the command line. It is based on Nokia QT 4.7.
Compatibility with QT 4.8 and 5.0 has been verified successfully.

Crash Dummy is a Java Web application to help IT professionals set up Java application server environments. It has several features to help make this easier, including simulating failures and diagnostics. Crash Dummy is particularly helpful for setting up complex clustered environments and monitoring infrastructure.